[datadogexporter] Use resource attributes for metadata and generated metrics

exporter/datadogexporter/config/config.go

@@ -26,7 +26,7 @@ import (
 
 var (
 	errUnsetAPIKey = errors.New("api.key is not set")
-	errNoMetadata  = errors.New("only_metadata can't be enabled when send_metadata is disabled")
+	errNoMetadata  = errors.New("only_metadata can't be enabled when send_metadata or use_resource_metadata is disabled")
 )
 
 const (
@@ -166,11 +166,20 @@ type Config struct {
 	// OnlyMetadata defines whether to only send metadata
 	// This is useful for agent-collector setups, so that
 	// metadata about a host is sent to the backend even
-	// when telemetry data is reported via a different host
+	// when telemetry data is reported via a different host.
 	//
 	// This flag is incompatible with disabling `send_metadata`
+	// or `use_resource_metadata`.
 	OnlyMetadata bool `mapstructure:"only_metadata"`
 
+	// UseResourceMetadata defines whether to use resource attributes
+	// for completing host metadata (such as the hostname or host tags).
+	//
+	// By default this is true: the first resource attribute getting to
+	// the exporter will be used for host metadata.
+	// Disable this in the Collector if you are using an agent-collector setup.
+	UseResourceMetadata bool `mapstructure:"use_resource_metadata"`
+
 	// onceMetadata ensures only one exporter (metrics/traces) sends host metadata
 	onceMetadata sync.Once
 }
@@ -185,7 +194,7 @@ func (c *Config) Sanitize() error {
 		c.TagsConfig.Env = "none"
 	}
 
-	if c.OnlyMetadata && !c.SendMetadata {
+	if c.OnlyMetadata && (!c.SendMetadata || !c.UseResourceMetadata) {
 		return errNoMetadata
 	}
 

exporter/datadogexporter/factory.go

@@ -81,7 +81,8 @@ func createDefaultConfig() configmodels.Exporter {
 			},
 		},
 
-		SendMetadata: true,
+		SendMetadata:        true,
+		UseResourceMetadata: true,
 	}
 }
 
@@ -99,23 +100,24 @@ func createMetricsExporter(
 		return nil, err
 	}
 
+	ctx, cancel := context.WithCancel(ctx)
 	var pushMetricsFn exporterhelper.PushMetrics
 
 	if cfg.OnlyMetadata {
-		pushMetricsFn = func(context.Context, pdata.Metrics) (int, error) {
-			// if only sending metadata ignore all metrics
+		pushMetricsFn = func(_ context.Context, md pdata.Metrics) (int, error) {
+			// only sending metadata use only metrics
+			once := cfg.OnceMetadata()
+			once.Do(func() {
+				attrs := pdata.NewAttributeMap()
+				if md.ResourceMetrics().Len() > 0 {
+					attrs = md.ResourceMetrics().At(0).Resource().Attributes()
+				}
+				go metadata.Pusher(ctx, params, cfg, attrs)
+			})
 			return 0, nil
 		}
 	} else {
-		pushMetricsFn = newMetricsExporter(params, cfg).PushMetricsData
-	}
-
-	ctx, cancel := context.WithCancel(ctx)
-	if cfg.SendMetadata {
-		once := cfg.OnceMetadata()
-		once.Do(func() {
-			go metadata.Pusher(ctx, params, cfg)
-		})
+		pushMetricsFn = newMetricsExporter(ctx, params, cfg).PushMetricsData
 	}
 
 	return exporterhelper.NewMetricsExporter(
@@ -148,23 +150,24 @@ func createTraceExporter(
 		return nil, err
 	}
 
+	ctx, cancel := context.WithCancel(ctx)
 	var pushTracesFn exporterhelper.PushTraces
 
 	if cfg.OnlyMetadata {
-		pushTracesFn = func(context.Context, pdata.Traces) (int, error) {
-			// if only sending metadata, ignore all traces
+		pushTracesFn = func(_ context.Context, td pdata.Traces) (int, error) {
+			// only sending metadata, use only attributes
+			once := cfg.OnceMetadata()
+			once.Do(func() {
+				attrs := pdata.NewAttributeMap()
+				if td.ResourceSpans().Len() > 0 {
+					attrs = td.ResourceSpans().At(0).Resource().Attributes()
+				}
+				go metadata.Pusher(ctx, params, cfg, attrs)
+			})
 			return 0, nil
 		}
 	} else {
-		pushTracesFn = newTraceExporter(params, cfg).pushTraceData
-	}
-
-	ctx, cancel := context.WithCancel(ctx)
-	if cfg.SendMetadata {
-		once := cfg.OnceMetadata()
-		once.Do(func() {
-			go metadata.Pusher(ctx, params, cfg)
-		})
+		pushTracesFn = newTraceExporter(ctx, params, cfg).pushTraceData
 	}
 
 	return exporterhelper.NewTraceExporter(

exporter/datadogexporter/factory_test.go

@@ -75,8 +75,9 @@ func TestCreateDefaultConfig(t *testing.T) {
 			EnvVarTags: "$DD_TAGS",
 		},
 
-		SendMetadata: true,
-		OnlyMetadata: false,
+		SendMetadata:        true,
+		OnlyMetadata:        false,
+		UseResourceMetadata: true,
 	}, cfg, "failed to create default config")
 
 	assert.NoError(t, configcheck.ValidateConfig(cfg))
@@ -132,8 +133,9 @@ func TestLoadConfig(t *testing.T) {
 				Endpoint: "https://trace.agent.datadoghq.eu",
 			},
 		},
-		SendMetadata: true,
-		OnlyMetadata: false,
+		SendMetadata:        true,
+		OnlyMetadata:        false,
+		UseResourceMetadata: true,
 	}, apiConfig)
 
 	defaultConfig := cfg.Exporters["datadog/default"].(*config.Config)
@@ -173,8 +175,9 @@ func TestLoadConfig(t *testing.T) {
 				Endpoint: "https://trace.agent.datadoghq.com",
 			},
 		},
-		SendMetadata: true,
-		OnlyMetadata: false,
+		SendMetadata:        true,
+		OnlyMetadata:        false,
+		UseResourceMetadata: true,
 	}, defaultConfig)
 
 	invalidConfig := cfg.Exporters["datadog/invalid"].(*config.Config)
@@ -256,8 +259,9 @@ func TestLoadConfigEnvVariables(t *testing.T) {
 				Endpoint: "https://trace.agent.datadoghq.test",
 			},
 		},
-		SendMetadata: true,
-		OnlyMetadata: false,
+		SendMetadata:        true,
+		OnlyMetadata:        false,
+		UseResourceMetadata: true,
 	}, apiConfig)
 
 	defaultConfig := cfg.Exporters["datadog/default2"].(*config.Config)
@@ -300,8 +304,9 @@ func TestLoadConfigEnvVariables(t *testing.T) {
 				Endpoint: "https://trace.agent.datadoghq.com",
 			},
 		},
-		SendMetadata: true,
-		OnlyMetadata: false,
+		SendMetadata:        true,
+		OnlyMetadata:        false,
+		UseResourceMetadata: true,
 	}, defaultConfig)
 }
 
@@ -385,8 +390,9 @@ func TestOnlyMetadata(t *testing.T) {
 			Key:  "notnull",
 			Site: "example.com",
 		},
-		SendMetadata: true,
-		OnlyMetadata: true,
+		SendMetadata:        true,
+		OnlyMetadata:        true,
+		UseResourceMetadata: true,
 	}
 
 	expTraces, err := factory.CreateTracesExporter(

exporter/datadogexporter/metadata/ec2/ec2.go

@@ -14,6 +14,7 @@
 package ec2
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/aws/aws-sdk-go/aws/ec2metadata"
@@ -23,11 +24,15 @@ import (
 	"go.uber.org/zap"
 )
 
-var defaultPrefixes = [3]string{"ip-", "domu", "ec2amaz-"}
+var (
+	defaultPrefixes = [3]string{"ip-", "domu", "ec2amaz-"}
+	ec2TagPrefix    = "ec2.tag."
+)
 
 type HostInfo struct {
 	InstanceID  string
 	EC2Hostname string
+	EC2Tags     []string
 }
 
 // isDefaultHostname checks if a hostname is an EC2 default
@@ -95,3 +100,26 @@ func HostnameFromAttributes(attrs pdata.AttributeMap) (string, bool) {
 
 	return "", false
 }
+
+// HostInfoFromAttributes gets EC2 host info from attributes following
+// OpenTelemetry semantic conventions
+func HostInfoFromAttributes(attrs pdata.AttributeMap) (hostInfo *HostInfo) {
+	hostInfo = &HostInfo{}
+
+	if hostID, ok := attrs.Get(conventions.AttributeHostID); ok {
+		hostInfo.InstanceID = hostID.StringVal()
+	}
+
+	if hostName, ok := attrs.Get(conventions.AttributeHostName); ok {
+		hostInfo.EC2Hostname = hostName.StringVal()
+	}
+
+	attrs.ForEach(func(k string, v pdata.AttributeValue) {
+		if strings.HasPrefix(k, ec2TagPrefix) {
+			tag := fmt.Sprintf("%s:%s", strings.TrimPrefix(k, ec2TagPrefix), v.StringVal())
+			hostInfo.EC2Tags = append(hostInfo.EC2Tags, tag)
+		}
+	})
+
+	return
+}

exporter/datadogexporter/metadata/ec2/ec2_test.go

@@ -64,3 +64,20 @@ func TestHostnameFromAttributes(t *testing.T) {
 	assert.True(t, ok)
 	assert.Equal(t, hostname, testInstanceID)
 }
+
+func TestHostInfoFromAttributes(t *testing.T) {
+	attrs := testutils.NewAttributeMap(map[string]string{
+		conventions.AttributeCloudProvider: conventions.AttributeCloudProviderAWS,
+		conventions.AttributeHostID:        testInstanceID,
+		conventions.AttributeHostName:      testIP,
+		"ec2.tag.tag1":                     "val1",
+		"ec2.tag.tag2":                     "val2",
+		"ignored":                          "ignored",
+	})
+
+	hostInfo := HostInfoFromAttributes(attrs)
+
+	assert.Equal(t, hostInfo.InstanceID, testInstanceID)
+	assert.Equal(t, hostInfo.EC2Hostname, testIP)
+	assert.Equal(t, hostInfo.EC2Tags, []string{"tag1:val1", "tag2:val2"})
+}